It is normal if the basal body temperature rises after ovulation by 0.3 to 0.5 °C or 0.54–0.9 °F. The increase in BBT is also natural in the case of a successful conception, after implantation or during the proposed menstruation.
Why does basal body temperature rise? Is it normal if the basal body temperature rises after ovulation or before menstruation? When does basal temperature rise after conception (during pregnancy)? Read the answers to all these questions in this article.
When is increased basal body temperature normal?
High BBT is a characteristic of the second phase of the cycle – the phase of the yellow hormone-secreting body (corpus luteum). It produces progesterone in large quantities, which:
- inhibits estrogen and increases BBT;
- is responsible for preparing the uterine endometrium for possible implantation;
- promotes saturation of uterine tissue and breasts with nutrients, etc.
In other words, progesterone prepares the female body for pregnancy and the carrying of a pregnancy. The yellow body is formed after the release of the egg, in place of the bursting follicle. And after this moment the basal body temperature begins to rise.
It is important(!): It is interesting that women can have both a sharp spasmodic increase in BBT after ovulation and gradual. There is one general rule – during normal hormone function, the basal body temperature will be established in the second phase in three days. The natural and proper difference is 0.3-0.5 °C or 0.54–0.9 °F.
A real example of a chart where the basal body temperature has risen sharply and established within the luteal phase in three days:
Here is a chart with a gradual increase in BBT:
If BBT rises before menstruation?
Normally, basal body temperature is kept elevated throughout the second phase, right up to the onset of menstruation or begins to slowly decrease 2 days before the start of the period. Here is an example of a chart without pregnancy with a decrease in BBT on the day before the start of a new cycle:
If on the contrary, the basal body temperature rises before menstruation – pregnancy is possible. In order to be sure that the rise in BBT occurred due to pregnancy, it is necessary to answer such questions:
- Is there a concomitant disease with an increase in general body temperature or localized – due to a local inflammatory process.For example, SARS, flu, stomatitis, hemorrhoids and other factors. Because it could give an elevated temperature as well.
- Have measurements been made in previous cycles? The fact is that such an increase can be an individual feature of a woman.
Note(!): In the absence of pregnancy, even if BBT rises before menstruation – with the start of a new cycle, or rather in 2–4 days, the basal body temperature will necessarily drop to the usual parameters of the first phase. Even with the onset of menstruation, the temperature has not dropped, and the tests still show a negative result, you need to take a blood HCG test.
The fact is that when the basal body temperature rises during pregnancy, it stably stays at the level of the second phase, and often even higher. And during the expected period the chart is consistently high.
This is how a pregnant BBT chart looks like with increasing and maintaining a high basal body temperature:
When the basal body temperature rises after conception?
If conception has successfully occurred (in the period from 2 to 24 hours after ovulation), the basal body temperature behaves as in the usual, non-pregnant cycle.
Three days after ovulation, it rises to the usual indicators of the second phase. The difference is that if conception has occurred, the corpus luteum does not collapse after 12-14 days, but continues to function and release progesterone.
It often happens that after the moment of implantation (7–10th DPO) there is another rise in basal body temperature. On the chart, it looks like this:
However, such an increase does not necessarily occur during normal pregnancy. In addition, if it happened, this is not a guarantee of possible pregnancy (shows in the first image). Only if BBT keeps elevated more than usual in the second phase can there be no doubt of pregnancy (another pregnancy symptoms here on ovulationdiary.com).
All readers should be happy with planning!